docs: def output_image(gandi, image, datacenters, output_keys, justify=14,
                   warn_deprecated=True):
      """ Helper to output a disk image."""
  
      for key in output_keys:
          if key in image:
              if (key == 'label' and image['visibility'] == 'deprecated' and
                      warn_deprecated):
                  image[key] = '%s /!\ DEPRECATED' % image[key]
              output_line(gandi, key, image[key], justify)
  
      dc_name = 'Nowhere'
  
      if 'dc' in output_keys:
          for dc in datacenters:
              if dc['id'] == image['datacenter_id']:
                  dc_name = dc.get('dc_code', dc.get('iso', ''))
  
                  break
  
          output_line(gandi, 'datacenter', dc_name, justify)